In Wheelock chapter 3, we find the following translation Latin-to-English exercise:

10. Sēcrētē amīcōs admonē; laudā palam.

I'm wondering about the accent on the word admonē. Should it be penultimate (admónē) or antepenultimate (ádmonē)? Of course, the form of monē is penultimate, since it's a two-syllable word. By the regular rules, I would expect it to be antepenultimate. Is there something special in the word because it has a prefix (ad-monēre)?